Effect of alloying elements on thermal stability of Aluminium-Cerium based alloys

Abstract

The strength of aluminum alloy decreases sharply with the increase of temperature. One of the major drawbacks of aluminum alloys is that it does not retain their mechanical properties at higher temperatures. To solve this problem, the high-temperature stability of the Al-Ce system is studied. The effect of alloying elements on the thermal stability of five different near eutectic Al-Ce based alloys, i.e., Al-12Ce, Al-12Ce-4Si, Al-12Ce-0.4Mg, Al-12Ce-4Si-0.4Mg and Al-12Ce-4Si-0.4Mg-0.25Sr alloys, were investigated. The alloys were heat treated at three different temperatures, i.e., 200 °C, 300 °C and 400 °C, to establish thermal stability. Binary Al-12Ce alloy consisting of α-Al and showed higher resistance to coarsening at all temperatures. The addition of Si helps retain the microstructure stability above 200 °C and the combined addition of Si and Mg increases the room and high-temperature strength up to 300 °C. The addition of Sr to quaternary alloy was not beneficial for enhancing thermal stability.